Facing an error on treeview control when code is transferred from one machine to another

Question

I am facing an error on the tree view control. Image is shown below.

What could be the potential reasons for it. I have transferred published code from one PC to another. The target machine is having windows 2008 server.

Everything is fine except the treeview control:

What could be the potential reasons for it?

Update

Here is an excerpt from my web.config

<system.webServer>
  <validation ntegratedModeConfiguration="false" />
  <handlers>
    <add name="ReportViewerWebControl" 
         path="Reserved.ReportViewerWebControl.axd" verb=""  
         type="Microsoft.Reporting.WebForms.HttpHandler" 
         resourceType="Unspecified" 
         requireAccess="Script" 
         preCondition="integratedMode" />
    <add name="ReportViewerWebControlHandler" 
         preCondition="integratedMode" 
         verb="" 
         path="Reserved.ReportViewerWebControl.axd" 
         type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
  </handlers>

Answer 1

This happens when you transfer files from one server to another but miss out the mapping for axd files.

Many controls embed images inside dlls and retrive them using WebResource.axd.

A common cause is moving from one version of IIS to another.

In IIS6 you would map it as:

 <httpHandlers>
  <add verb=”Get” path=”WebResource.axd”
   type=”System.Web.Handlers.AssemblyResourceLoader” />
 </httpHandlers>

However in IIS7 you will need

<system.webServer>
 <modules>
 </modules>
 <handlers>
  <add name=”webresources” verb=”Get” path=”WebResource.axd”
   type=”System.
   Web.Handlers.AssemblyResourceLoader” />
 </handlers>
</system.webServer>